OK, this makes my head hurt. TiddlyWiki is a self-contained, client-side Wiki written entirely in HTML, CSS and JavaScript. Unlike most wikis, there’s no server for a TiddlyWiki — when you download a page you have your own local copy of the entire wiki, and any changes you make affect only that local copy. It’s not a collaborative authoring space, at least not in the traditional sense, but it’s useful for taking notes or maintaining a set of HTML pages that you later want to upload to a server. I’m impressed by the numbers of features and slickness of the interface given that it’s “just” JavaScript (note to self: JavaScript is now a real language). It also has an interesting navigation that’s something of a cross between a wiki and a blog, where clicking on a link inserts the relevant post into the main page you’re reading. It reminds me of Radio Userland‘s Live Outline Tool, though unfortunately that includes the fact that I find it easy to get lost in both.

The full implications of this kind of client-side Wiki didn’t really hit me until I briefly wondered where I could download a copy, only to realize I already had just by visiting the site. As their instructions point out, just do “Save Webpage As…” (either of their main page or of a blank version) and you’ve got your own copy, ready to edit.